US6574581B1 - Profile based method for deriving a temperature setpoint using a ‘delta’ based on cross-indexing a received price-point level signal - Google Patents

Abstract

A method for adjusting a plurality of controlled subsystems in a building or plant that facilitates cooperative energy usage with a utility provider. By referring to a single profile of adjustments that correspond to changes in the value of a utility signal and distributing this to each relevant controller for each subsystem, a single setback delta can be applied to each subsystem for each change in utility signal value (i.e., pricing information). Alternatively, multiple profiles can be used to provide for firmer control and thereby allow for different zones to respond differently to a single change signal sent by the utility provider.

Description

This invention relates to reducing energy costs (in conjunction with time-of-use pricing with rates that vary according to energy costs) and has particular application to home control and building control in general and is useful in areas supplied by electric utilities that wish to engage in demand side management of their area.

BACKGROUND OF THE INVENTION

As it becomes more expensive for electricity providers to increase generation, distribution and transmission capacity, a number of strategies for coping with increasing electrical demand have emerged. One of these is called demand side management in which the users of electricity themselves are adapted to reduce the amount of electricity they use during times of peak power usage as well as in other similar situations. The invention herein provides a way to adapt users of electricity to reduce their demand responsive both to predetermined rate information established periodically by the local utility and to real time changes in rates. Thus by communicating the (time-of-use) energy price rate to a control system within the customer's premises, the control system can reduce the energy consumption within the premise during times when the cost of energy is high. The utility can reduce the necessary generating capacity for a given area, and the users of that power can reduce their cost of buying it at the same time.

Previous ways to deal with related problems of reducing energy consumption in buildings in general are described in U.S. Pat. Nos. 4,510,398; 4,916,328 and 4,909,041. Nevertheless there is no reason why this invention could not be used in non-residential buildings or even in industrial processes that consume electric power.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a conceptual block diagram of one form of the preferred embodiment of the invention.

FIG. 1A is a conceptual block diagram of a preferred embodiment bus structure for the invention.

FIG. 2 is a conceptual block diagram of the power supplier's or company's interface to a controller in one preferred embodiment of the invention.

FIG. 3 is a two-dimensional overview diagram of a house which may be employed having a number of systems controllable in accord with one of the preferred embodiments of the invention.

FIG. 4ais a model of the display used by a preferred embodiment of this invention.

FIGS. 4b-r(there is no FIG. 4j) are ordered sets of displays in accord with a preferred embodiment of this invention available to the user through the display illustrated in FIG. 4a.

FIG. 5 is a partial example profile list representing a heating system for use in a house in accord with a preferred embodiment of this invention.

FIG. 6 is another preferred embodiment profile list.

SUMMARY OF THE INVENTION

A controller for controlling the energy-consuming equipment and systems in a building which may benefit from changing utility rate information is taught in this invention. In a memory, the controller stores price point profiles that contain information indicating the appropriate setpoint-delta, or setpoint limit for each system under control by the controller for each price point. A price point may be called a tier, a rate change or rate, or a critical change, depending on an agreed-upon or established convention for the utility. Some of this information may change over the course of a day or week, and some may be real-time driven by signals provided by the utility service provider. In the main, this invention is concerned with the last mentioned kind of price change information but does also accommodate others.

A processor is connected to produce adjusted setpoint signals or adjust the setpoint for each of the controlled subsystems. All the changes will occur based on the predetermined information located in the pricing profiles stored in memory.

The controller has a gateway for communicating the pricing point signals to the controller from the utility. A significant amount of variability is available to the designer employing the invention described herein, which should only be considered limited by the claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 describes thecontrol system10 consisting of acontroller11 which, in the preferred embodiment is organized to include auser interface12,memory subsystem14,heating plant interface15a,air conditioner interface15band power line interface4; each of which communicate with aprocessor16, either through direct connections or via acontroller bus5. In the preferred embodiment, a communications interface to the utility (called an external interface)13 is connected to the controller through power line interface4. Thecontroller11 may send output signals to heatingplant15a,air conditioner15b,other systems6 and7, and theuser interface12 as desired by the user for controlling the various systems that are controlled by thecontroller11.

A preferred bus structure for setting up the interfaces between the controller and the other components is described with reference to FIG. 1A. A number of companies currently provide a universal interface for home control, for example “H-Bus” (provided by Honeywell Inc.) which here could operate ascontroller bus81. This bus would allow for communications between the various components attached to that bus of the various control and information signals and data which need to be passed the units at the system. The H-Bus™ system provided by Honeywell, for example, provides for a DC balanced, limited set of code words which all systems may read and which only appropriate systems will react to. Alternative forms of busses are well known and, as the art develops, new busses will become known and the most efficient bus for the appropriate situation should be employed by the designer. The external interface to theutility86 in the preferred embodiment interfaces with a utility providedcoaxial cable84 although there are many ways the utility pricing signal could be fed into the system8 (for example,RFI86acould receive RF signals). Likewise, fiber-optic cable or the power lines themselves may be used if desired.

In the illustration of FIG. 1A, H-Bus™ interface91 merely provides for communications between two busses,81 and82, wherebus82 may be, alternatively, another H-Bus™, or perhaps even a power line used as a bus. Thebus82 side ofinterface91 will, of course, have to be adapted to the particular situation. In this situation, for example,controller17 could connect directly to bus82 i it were an H-Bus™, andinterface91 would not be needed.

In some embodiments this communication could be two-way, to also provide data back to the utility. Many different forms of external interface may be employed without going beyond the scope of this invention and these are described in more detail with reference to FIG.2. The controller87 (11) resides on both aserial bus82 and on the power line which here is also used for communicating data. Theuser interface12 preferably also resides on the sameserial bus82. A power line interface (PLI) (which may also be provided to all communicating systems on the power line) will, in the minimum configuration for using a power line interface, provide signals from the controller through thepower line83 to systems that function through power line controllers (for example, LSMcontroller module88 which controls load89). In the simplest case, a light (which might be load89) could be turned on or off at various times of the day or according to various other factors taken into consideration by thecontroller88. Many other configurations based on this example should be readily apparent to those of ordinary skill in this art.

Referring now to FIG. 2, potential forms of interface from thepower company20 to thecontroller11 are described. Each one of these has strengths and weaknesses which may be overcome by others. Atelephone line25 may connect aninterface13ato the controller in a house or in a building, for instance, or adirect line21 may go directly to theinterface box13dwhich connects to thecontroller11. If the power company opts to send signals through thepower lines24 themselves tointerface box13b,a number of problems may develop with the carrying of such signals through the transformer network currently employed by electric utility companies, for example. Some combination of power line and radio wave signals may be employed such as, for instance, having a radio receiver at every transformer in a locality wherein the radio receiver would send an appropriate signal over the power lines after the transformer into the individual's houses or buildings or, a small area may be blanketed in which each house has abox13cwith anantenna13dwhich receives RF signals from anoutput antenna23 from the power company online22. As with the previous two diagrams, many combinations of the above will occur to the designer of ordinary skill in the art without leaving the scope of this invention. In the presently preferred embodiment, the utility signals the user's facility/home/building via a coaxial cable. This signal is transferred into the facility's internal power lines, where a power line interface receives the signals.

In general, any value laden signal could be called a “tier” signal. So, for example, if the utility provider sent signals corresponding to real-time price data, the processor would have to be modified to respond to such data rather than to a “tier” level signal. It is presently felt that the simplicity provided by using a limited number of tier signals affords use of simpler processors and for that reason it is present preferred. The practitioner of ordinary skill can easily adapt this invention to any type of consistent signaling mechanism.

FIG. 3 has a collapsed floor plan of ahouse30 andpool40 showing various subsystems31-39 and41, which are controllable through the use of this invention. Theair conditioning subsystem31 and the furnace or heating subsystem (preferably electric)34 generally will work together through a thermostat (not shown). In sophisticated houses a verticalblind turning motor32 could be provided to reduce heat load or increase heat load provided by the sun on rooms in a building through a window. Various lighting subsystems may be controlled individually such as plant lights33 in an arboretum,exterior security lights38aand38cand exterior pool lights39a-c.Ahot water heater35, washer/dryer36,refrigerator37 andpool pump41 provide other examples of subsystems which maybe controlled by use of this invention. By quickly referring back to FIG. 2, it can easily be seen that various controller interfaces such as13a,15d,13band16 may be employed for controlling these subsystems of the user's homes.

For example, thesecurity light system38aand38bmay be turned on at all times during the evening hours, regardless of cost, in a high-crime neighborhood. Likewise, beyond a certain price tier or level, thepool pump subsystem41 and outdoor pool lights39a-cwould likely be turned off any time price of power for them reaches a certain tier. As would occur to the reader, there may be times that an owner/occupier of a building space would prefer to override a standard program and this can be included as well.

Some systems of the typical house however, will preferably have their setpoints adjusted rather than either being simply turned on or off based on the price point provided by a utility. The most common example currently would be the heating and air conditioning system in the typical residential home or commercial building. Typically, setback thermostats have become well distributed within the United States and are well known elsewhere. These thermostats allow for programming by the occupant to accommodate his schedule. The simplest version would have two modes or periods, a high and a low, but most have at least four. These have been called various things but commonly may be referred to as period: WAKE, LEAVE, RETURN and SLEEP, which may roughly be interpreted as warm up the house in the winter because the occupant is waking, the occupant is leaving so reduce power consumption for maintaining the comfort in a space, the occupant is returning and wants a higher level of comfort, and the occupant expects to be asleep and therefore a different temperature and comfort level is required. An exemplary unit is produced by Honeywell Inc. and goes by the trademark “Magicstat™”, and provides these four modes for the occupant to program.

The invention herein, with reference to this subsystem of heating, ventilation and air conditioning control may operate at various levels of complexity depending upon the subsystems and controllers available in the house or building. In general, it may function in one of two ways. First, it may require a list of setpoints for each controlled subsystem (furnace, air conditioner, lighting systems, refrigerator cycling time, etc.) for each price point or tier which the utility may provide. Second, it may simply maintain a list of offsets for each price-point.

For the example of the first, refer to FIG. 5 in which the profiles for four levels; A, B, C and D corresponding to low price, medium price, high price and critical are shown for the furnace. For purposes of explanation, assume this iselectric furnace34 andair conditioner31 inhouse30 of FIG.3.Zone1 may be the bedrooms. For user convenience, it may be called “Master BR” or some other mnemonic chosen by the user.Zone2 may be the kitchen andzone3 may be the dining room area. Each one of these profiles A-D should exist for each mode available to the user. In those illustrated in FIG. 5, the sleep mode is the only mode indicated. Thus, if the occupant expects to be sleeping, the temperature preferred for the bedroom at the lowest price point available from the utility (Price-Low) would be 68° for the bedrooms in this user's most desirable comfort. The kitchen and living room are not being occupied and therefore a cooler temperature may be perfectly all right for this user, 60° Fahrenheit forzones2 and3, respectively. This example assumes wintertime weather in which the outdoor air temperature is, perhaps, 20° Fahrenheit. Profile B shows the setpoints for the heater in the sleep mode at the medium tier price. Profile C shows the three-zone setpoints in the sleep mode at the high price point. If the utility provider so desires and there are peak demand periods which must be dealt with and users who don't deal with them through this demand-side management must pay an exorbitant price may be summarized in the profile critical - D, which in the sleep mode allows the bedrooms to reach 60° Fahrenheit and the living room and dining room area to reach 48° Fahrenheit. If a critical tier is employed by the utility provider, it may specify the setpoints itself.

For an example of the second method of profile usage, see FIG. 6 in which again a partial layout of profile (here A, B, A₁and B₁) is shown to demonstrate the concept employed here. FIG. 6 contains two mode partial profile sets; A, B for a “WAKE” mode and A₁, B₁, to contain the information for the first two price levels for the “AWAY” mode. In this second method, note that a single offset is applied to the entire set of subsystems affected.

It is anticipated that this might, in the ordinary homestead, be limited to one or two subsystems, i.e., the HVAC and perhaps the hot water heater. In such cases where the first applications of this invention are likely to be found, it seems most advantageous not to add the memory to hold different offsets for different zones. Accordingly, this is the presently preferred embodiment.

In the FIGS. 4a-r,auser interface panel50 contains adisplay area51, a set of four soft keys52a, b, c, d,and twohard keys53, Select and Back. Various configurations for data on thedisplay51 may be provided by other designers but in the preferred embodiment, arrows orother symbols55 indicate the functions of thesoft keys52a-dbyreference56 associated with eachsuch symbol55. Where a display merely indicates information about the user's options, such as a help screen, a display configuration such as that shown in FIG. 4cmay be provided in the preferred embodiments. In other cases,information57 and a zone name ormessage54 is preferably provided on thedisplay51 as in FIG. 4a.For ease of explanation,keys52 and53 contain information regarding their function which would not generally be available to the user. For example, in FIG. 4a,key52ahas two “+” signs indicating that the function of softkey52ais to increase the amount of warmth, and key52bhas two “−” signs to show that the amount of warmth should be decreased and that the setpoint should be reduced. These “++” and “−−” keys will not be on the user touch pad but are included in these drawings to provide redundant information to the reader in order to facilitate the grasp of the inventive concepts of this document.

The use of softkeys allows the user to control the system without requiring a complicated or expensive user interface such as a general-purpose computer. However, general purpose computers or other interface devices may be used if desired. Also if desired, the utility may provide for the actuation of particular profiles within individual spaces or homes directly, but this would require such a utility to maintain an active database and provide a method by which the users could modify that database to their own desires on some kind of acceptable basis.

Other symbols drawn onto the keys such as in FIG. 4bindicate that a display is available at another level. N/A would indicate that that particular key cannot perform any function with this particular display. N/S indicates a feature not shown or described.

Starting with the display onpanel50, the user is provided with “options” to review schedules and profiles by selecting softkey52a“month-to-date-electric bill” by52b,“energy rate adjustments” by52c,and “help” by key52d.In this level the user may go back to the display of FIG. 4aby pressing the key53 “back”. No other options are available to the user from the panel as set up in FIG. 4b.

In FIG. 4c,a help screen would be the result of the user selecting softkey52din FIG. 4b.By selectingkey53 “select” the user would be moved to review the display of FIG. 4dwhich concludes the information available for this help function.

Moving on to FIG. 4d(the next level inward), the user would then select key53 “back”, leading him to the display illustrated in FIG. 4eto review the schedules and profiles. Another help screen is available by selecting key52dat this stage, and a connection to the controller may be had by the user by selectingkey52c.FIGS. 4fand4gshow the help screens available from FIG. 4e.FIG. 4hshows an electric bill. FIG. 4ishows the user what this means. FIG. 4kshows the user what his energy rate adjustments are for heating and cooling, allows him to select more energy rate adjustments by pressing key52d,or changing the adjustments for the heating and the cooling by selectingsoftkeys52a-c.Only the “high” rate setting is shown in these figures.

In FIG. 41, the user is allowed to go back to factory settings if desired. In FIGS. 4m-p,this is all explained (a “help” function).

By use of a simplified user interface such as the one described in these figures, user options may also be limited if desired, but they are not in the preferred embodiment. For example, in FIG. 4q,it can be seen how the user would adjust for the high adjustment for the option of FIG. 4k.In FIG. 4r,the user can be shown that he is trying to exercise control beyond the limits agreed to between himself and the utility. The display of FIG. 4r,in the preferred embodiment, will appear whenever the user attempts to go beyond his pre-agreed limits. This type of display may be used for other than profile out of bounds commands too. For example, the user may attempt to override a DLC signal at a time or for a load for which this is not permitted under the agreement with the utility. In such event a screen that says “direct control of this load is not permitted at this time” would be an appropriate form of message.

Having set out the various elements of the system and how the interface with the user should operate in a preferred embodiment of the invention and described how a multiplicity of alternative arrangements may also be preferred and within the scope of the present invention, a detailed descriptive of the interactive operation of the system should now be had.

Thus, for example, if at 12 midnight an electric utility were to pull substantial load generation capacity offline, say, for maintenance. It would then send out a “high price” signal over whatever communication pathway (FIG. 2) has been selected by thepower company20 to the utility interface to the customer's home, building, business or industrial facility (external interface, i.e.,13, FIG. 1 and 1a). Thecontroller11 receives this information overbus17 or directly from theexternal interface13, whereuponcontroller11 refers to the profiles (FIG. 5) stored in memory14 (an internal part ofcontroller11 in FIG.1A). The controller maintains a current status set of registers including a mode indicator and an active setpoint indicator. Using the mode indicator reference, the controller searches memory for the “high price” profile for each subsystem under its control. Thus, inzone1, the offset of −3° Fahrenheit is provided to the subsystem controller forzone1 with reference to the current active setpoint of 68° Fahrenheit. With reference tozone2, no offset is provided and in reference tozone3, an (−2°) offset is provided.

Alternatively, and in the most preferred embodiment, a very small profile set may be stored as in FIG. 5a.Here the 3° offset is applied to all units under control of the system for the “high price” signal.

A set of 16 drawings is included as an Appendix which supplies the presently most preferred embodiment of the Graphic User Interface first described in FIG. 4aet seq.

The invention should not be considered limited, except as set forth in the following appended claims.

Claims (31)

What is claimed is:

1. A method for controlling the energy usage in a building having controllers responsible for maintaining one or more subsystems in the building at a setpoint comprising:

responding to a rate change signal received by a utility by controlling variable loads with reference to a profile of offsets, an appropriate offset stored for each possible rate change, by

a) looking up the appropriate offset for each variable load,

b) submitting the appropriate offset to the controller for each subsystem

c) modifying the setpoint associated with each subsystem by the appropriate offset.

2. A method for controlling the energy usage in a building having controllers responsible for maintaining one or more subsystems in the building at a desired setpoint comprising:

responding to a rate change signal by controlling variable loads with reference to a profile of offsets, an appropriate offset stored for each possible rate change, by looking up the value of the appropriate offset for each rate change signal received and submitting that offset to each controller for each subsystem, the setpoint associated with each subsystem being thereafter modified by the appropriate offset.

3. A method as set forth inclaim 1 wherein step a) is performed iteratively for each subsystem having a stored profile.

4. A method as set forth inclaim 1 wherein steps a) and b) are performed iteratively for each subsystem having a stored profile.

5. A method as set forth inclaim 2 wherein each subsystem receives said appropriate offset individually.

6. A method as set forth inclaim 2 wherein each subsystem is sent said appropriate offset at substantially one time.

7. A method for cooperatively responding to rate changes initiated by a utility including a prearranged pricing schedule and real-time pricing, including

a) adjusting a user-defined setpoint by an offset in accord with a user-defined schedule when

i) a prearranged pricing change occurs, and

ii) upon receipt of a real-time pricing notification signal,

b) sending a signal indicative of the offset after every prearranged pricing change occurrence and upon receipt of a real-time pricing notification signal to each subsystem controller responsive to changes in the user-defined setpoint.

8. The method set forth inclaim 7 wherein step a) is accomplished by:

responding to rate changes received from a utility by controlling variable loads with reference to a profile of offsets stored for each possible rate change, by

a) looking up the appropriate offset for each variable load,

b) submitting the appropriate offset to the controller for each subsystem

c) modifying the setpoint associated with each subsystem by the appropriate offset.

9. The method set forth inclaim 7 wherein step a) is accomplished by:

responding to a rate changes by controlling variable loads with reference to a profile of offsets stored for each possible rate change, by looking up the appropriate offset for each rate change received and submitting that offset to each controller for each subsystem, the setpoint associated with each subsystem being thereafter modified by the appropriate offset.

10. The method set forth inclaim 1 wherein at least one variable load relates to an individual zone in the building.

11. The method set forth inclaim 8 wherein at least one subsystem is controlled by a zone controller.

12. A method for controlling one or more energy consuming subsystems with a controller by maintaining each subsystem at a setpoint, comprising:

storing in the controller a price profile for all subsystems, the price profile correlating a cost of energy with an offset from the setpoint;

receiving from a utility which supplies energy one or more signals reflecting a current cost of the energy supplied;

retrieving from the price profile stored in the controller the offset correlated to the cost of energy at the current time for each subsystem;

adjusting the setpoint for each subsystem by the offset whereby the energy used by the subsystem is altered according to the offset.

13. The method ofclaim 12 wherein the signal reflecting the current cost of energy comprises a specific energy rate.

14. The method ofclaim 12 wherein the signal reflecting the current cost of energy comprises a signal reflecting energy demand at the utility.

15. The method ofclaim 12 wherein the signal reflecting the current cost of energy comprises a signal indicating a change in the cost of energy from the current cost.

16. The method ofclaim 12 wherein the signal reflecting the current cost of energy comprises a signal indicating a change in the cost of energy from a base cost.

17. The method ofclaim 12 wherein the signal reflecting the current cost of energy reflects a predetermined pricing schedule.

18. The method ofclaim 12 wherein the step of adjusting the setpoint for each subsystem comprises sending a new setpoint signal to each subsystem.

19. The method ofclaim 12 wherein the step of adjusting the setpoint for each subsystem comprises sending the offset directly to the subsystem.

20. The method ofclaim 12 wherein the each subsystem receives the offset sequentially.

21. The method ofclaim 12 wherein the subsystems receive the offset in parallel.

22. A method for controlling one or more energy consuming subsystems with a controller by maintaining each subsystem at a setpoint, comprising:

storing in the controller a plurality of price profiles shared among the subsystems, the price profile for each subsystem correlating a particular cost of energy with an offset from the setpoint;

receiving from a utility which supplies energy one or more signals reflecting a current cost of the energy supplied;

retrieving from the price profile stored in the controller the offset associated with the current cost of energy for each subsystem;

adjusting the setpoint for each subsystem by the offset whereby the energy used by the subsystem is altered based on the offset.

23. The method ofclaim 22 wherein the signal reflecting the current cost of energy comprises a specific energy rate.

24. The method ofclaim 22 wherein the signal reflecting the current cost of energy comprises a signal reflecting energy demand at the utility.

25. The method ofclaim 22 wherein the signal reflecting the current cost of energy comprises a signal indicating a change in the cost of energy from the current cost.

26. The method ofclaim 22 wherein the signal reflecting the current cost of energy comprises a signal indicating a change in the cost of energy from a base cost.

27. The method ofclaim 22 wherein the signal reflecting the current cost of energy reflects a predetermined pricing schedule.

28. The method ofclaim 22 wherein the step of adjusting the setpoint for each subsystem comprises sending a new setpoint signal to each subsystem.

29. The method ofclaim 22 wherein the step of adjusting the setpoint for each subsystem comprises sending the offset directly to the subsystem.

30. The method ofclaim 22 wherein the each subsystem receives the offset sequentially.

31. The method ofclaim 22 wherein the subsystems receive the offset in parallel.

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